Fuel injector



June 22, 1965 H. l. FULLER ET AL 3,190,561

FUEL INJECTOR Filed June 28, 1962 so 66 55 60 Fr q Z 65 62 57 59 QEUW? ys'ln "il 64 ig'l-l l\\` 50 s4 gli@ n 7g 89 lill'. w

\ I9 ATTORN S United States Patent O pas 3,196,561 FUEL lNdEtlllR Harlan i. Fuller and Millard it. Thomson, Sidney, NX., assignors to The Bendix Corporation, Sidney, NY., a corporation of Delaware 'Filled .func 28, 1%?, Ser. No. 296,@28 22 Claims. (Cl. 239-90) This invention relates to a novel fuel injector, and more particularly relates to a unit fuel pump-injector. The injector of the invention may be used to advantage, for example, in supplying the timed fuel requirements of a cylinder of an internal combustion engine.

The invention has among its objects the provision of a novel fuel injector, such injector being particularly characterized by its simplicity, the small number of its parts, and its economy of manufacture.

A further object of the invention lies in the provision of an injector of the type described having improved means for adjusting the quantity of fuel delivered at each cycle of the injector.

Another object of the invention resides in the provision of a fuel injector having novel mechanism for retaining the pump plunger of the injector in the housing thereof.

Yet another object of the invention resides in the provision of a novel improved mechan-ism for laterally guiding the outer free end of the pump plunger, whereby to relieve the pump plunger of lateral forces which might be imposed thereon by the plunger operating mechanism.

Still a further object of the invention lies in the provision, in a fuel injector of the type indicated, of an improved check valve for insuring a sharp cut-off of the delivery of fuel at the end of each fuel injecting cycle.

The above and further objects and novel features of the invention will more fully appear from the following description when the same is read in connection with the accompanying drawings. It is to be expressly understood, however, that the drawings are for the purpose of illustration only, and are not intended as a definition of the limits of the invention.

ln the drawings, wherein like reference characters refer to like parts throughout the several views,

FIG. l is a view in perspective of an illustrative fuel injector made in accordance with the invention, the injector being shown in combination with a cam for operating the pump plunger of the injector and a fragmentarily shown control linkage for the injector;

FIG. 2 is a view in axial section on an enlarged scale through the injector of FlG. l;

FIG. 3 is a view in transverse section through the injector, the section being taken along the line 3-3 of FG. 2;

FIG. 4 is a view in elevation of the illustrative injector, the view being taken in a direction from left to right in PG. 2; and

EEG. 5 is a view in perspective of the injector plunger and the plunger positioning and adjusting parts associated therewith, the injector casing and the fuel inlet and fuel bleeding ports of the injector being shown in phantom lines, the valve plunger being shown adjusted to a typical operating position and at the end of its fuel intake stroke.

The illustrative fuel injector of the present invention may be used to advantage, for example, to supply the timed fuel requirements of an internal combustion engine of the spark ignited or diesel type. One such fuel injector is provided for each of the cylinders of the engine, the pump plunger of the injector being operated at the proper time by means such as a cam either acting directly upon the pump plunger, as shown, or indirectly thereupon as through a push rod and rocker arm. The fuel injector is preferably mounted directly upon the engine block so that the nozzle of the injector protrudes into the combustion Patented .fune 22, 1965 lCe chamber of the cylinder. For simplicity, the engine with which the injector is designed to be associated is omitted from the drawing.

Turning now to the drawings, the illustrative fuel injector, which is designated generally by the reference character 10, is shown as being actuated by a cam 11 mounted on a cam shaft 12. lf the engine to be supplied is of the four-stroke cycle type, the cam shaft 12 is driven at 1/2 crank shaft speed. Cam 11 has a rise or lobe 14 thereon disposed at the proper angle with respect to shaft 12 for the injector 1li to begin its fuel injecting operation at the proper time in the engine cycle.

injector 19 has an elongated generally cylindrical body 15 having a central bore 16 therein. A reciprocable plunger 17 is accurately fitted in bore 16, such plunger reciprocating from its outermost position (FIG. 2) to its innermost position during each of its fuel injecting strokes. Fuel is supplied to bore 16 below the inner end of the plunger when the plunger is in the position of FIG. 2 through a fuel supply pipe 19 which is connected to a hollow boss 20 integral with casing 15 of the injector. A radially disposed fuel inlet port 21 connects the space between the lower end surface 22 of plunger 17 to the supply pipe 19 when plunger 17 is in its outer or raised position. The fuel supplied to the injector through pipe 19 is preferably under a moderate pressure produced, for example, by a varied pump or impeller.

The lower end of casing 15 is provided with a counterbore coaxial with bore 16, the sidewall of the counterbore being threaded at 24. The upper transverse end 2.5 lof such counter'bore is at, and sealingly interiits with the upper surface of a fiat disc or plate Z6 which is thrust upwardly thereagainst. Plate 26 has a central passage 27 therein, such passage being of somewhat smaller diameter than bore 16. Mounted coaxially of casing 15 and plate 26 is a nozzle and valve body generally designated 29. Body 29 has a lower or inner end 3? of somewhat smaller diameter than its upper end 31; end 31 of body 29 is of cup-like shape and contains a check valve to be described. Member 29 is held in the position shown by a retaining nut or sleeve 32 having an externally threaded upper end 34 received in the counterbore at the lower end of casing 15 and threadedly engaging threads 2d on the sidewall thereof. The lower end of sleeve 32 is necked inwardly so as accurately to fit about portion 3d of the nozzle and valve body. The plate 26 is snugly received within the upper end of portion 34 of the sleeve, and is thrust upwardly by engagement therewith by the upper end of portion 31 of the nozzle and valve body. When the sleeve 32 is screwed upwardly into the casing 15, plate Z6 is thrust into sealing engagement with surface of the counterbore in the casing and the upper end of member 31 sealingly engages the lower surface of plate 26. A packing 36 disposed in an annular groove about the upper end of member 34 precludes the leakage of fuel through the threaded joint between member .3f-i and the casing.

The chamber 37 within the upper end of the nozzle and valve body has a lower end 39 formed in such body, the upper end of the chamber being dened by the flat transverse bottom surface 0f plate 26. A vertically movable check valve member, generally designated 40, has an enlarged head 41 having a flat upper end surface 42 which sealingly engages the lower surface i4 of plate 26 about the passage 27 when the valve member is thrust upwardly into the position shown in FIG. 2 by a coil compression spring 46. Spring 46, which is telescoped about the valve member, has its upper end engaged beneath the shoulderV `on head 41 of the valve member, a central stem on the valve member 4@ being telescoped within the spring. When the upper end of the valve member iti is subjected to sufhcient pressure of uid upon an injecting stroke of plunger 17, the valve member moves downamasar wardly against the upward bias of spring 46 suciently for fuel to flow downwardly through passage 27 into chamber 37 and thence outwardly through a further passage 47 in the inner or lower portion 30 of the nozzle and valve member to the still smaller nozzle outlet 49 which sprays the fuel into the engine cylinder. It will be seen that the described check valve is formed between flat surfaces (the lower surface of plate 26 and the upper surface of the head 41 of the valve member) and that the valve member is permitted a substantial freedom of motion both laterally and angularly in its chamber during the unseating and seating of the valve member. Such at surfaces are particularly easy to form with great accuracy; this, taken with the freedom of motion of the valve member, provides a check valve which is not only simple and economical to make but which functions reliably to cut off the flow of fuel sharply upon cessation of fuel injection by the plunger 17.

The upper end of casing 15 is provided with a smooth walled counterbore t) of relatively large diameter. Accurately and slidahly fitting within counterbore 50 is an inverted cup-like member 51 having a circular cylindrical outer surface. A coil compression spring 52 disposed between the inner transverse end of counterbore 51B and the upper transverse end of guide member 51 constantly urges the guide member toward its upper or outer position shown in FIG. 2. The upper end of pump plunger 17 is of reduced diameter as shown at 54, portion 54 of the plunger extending axially through spring 52 and being connected to guide member 51 in the following manner: The outer end of plunger 17 beyond portion 54 thereof is provided with an enlarged head 55. Head 55 is of such diameter as freely to pass through a central passage 56 in the upper end wall 57 of member 51. The upper or outer surface of end wall 57 is provided with a shallow circular cylindrical seat 59 which receives a pump plunger retainer and cam follower 60. Member 60 is generally in the form of an inverted cup having an upper end wall 61, which is engaged by cam 11, and a depending skirt 62. The skirt is slotted at one side thereof, as shown at 65, and is provided with an inwardly directed flange 64 throughout its unslotted portion. The space 66 within member 60 receives head 55 on the plunger, member 60 being mounted on the plunger by depressing guide member 51 while maintaining the plunger 17 in its elevated position, following which the member 60 may be slid laterally onto head 55. When member 51 is then released, the bottom end of cam follower 69 ts accurately within seat 59 therein. As a result of such construction, the upper or outer end of plunger 17 is accurately maintained coaxial of housing 15, and any side thrust imposed upon cam follower 6i) by the cam 11 is borne by the broad engaging surfaces of counterbore 50 in housing 15 and the outer peripheral surface of guide member 51.

The injector of the present invention is provided with means whereby the quantity of fuel injected thereby at each operative stroke of the plunger 17 may be varied. Such variation is effected by releasing fuel injecting pressure from the chamber beneath the inner end of the plunger at varying times during the injecting stroke of the plunger. Such pressure releasing means are shown as including a passage -67 disposed axially of pump plunger 17 from the inner face 22 thereof, passage 67 communieating with a short radial `passage 69. Other suitable known means, such as a longitudinal slot in the surface of the plunger, may be used in lieu of passage 67, 69. A

helical or angular slot 70 is provided on plunger 17, the

slot being positioned to connect with the outer end of passage 69 or with the upper end of such longitudinal slot. A pressure releasing or by-passport 71 is disposed in the sidewall of housing above inlet port Z1 and in position to be covered by the imperforate portion of the plunger when the plunger is retracted into its uppermost position shown in FIG. 2. In such position of the plunger the lower face 22 thereof lies above inlet port 21. When the plunger is impelled downwardly by cam 11, the chamber beneath the plunger is closed once the lower end Z2 of the plunger has passed the lower edge of inlet port 21. Fuel in the chamber is then subjected to injecting pressure which overcomes the opposition of check valve 4t? and forces the fuel past the valve outwardly through passage 47 and nozzle opening 49. Such injection of the fuel continues until at least a portion of the helical slot 70 on plunger 17 overlaps a part of port 71; when this occurs, the fuel remaining in the chamber beneath the plunger escapes therefrom through passages 67, 69, groove 7d, and port 71, Iso that the check valve 40 again closes.

The time in the injecting cycle at which the fuel in the pump chamber is thus released may be varied by the turning of the plunger 17 to vary the point in the stroke at which groove '70 overlaps port 71. Such turning of the plunger therefore provides a means for varying the amount of fuel delivered by the injector at each stroke of plunger 17.

Turning of the plunger is effected by the following novel simplified mechanism. Housing 15 is provided with a transverse slot 72 of appreciable axial width, such slot being located in the housing at a substantial distance axially outwardly of the chamber beneath the plunger. Slot 72, which extends from the outer surface of the housing inwardly thereof somewhat past the cylindrical bore 16 therein, is generally of sector shape in its radially outer portion and is generally of circular cylindrical shape in the portion thereof surrounding bore 16. The plunger 17 is provided with a flat axially extending surface 74 on one side thereof, surface 74 terminating at its bottom end at a right angle shoulder 75. Snugly received within slot 72 in the housing is a bifurcated control plate 76, the inner end 77 of which is in the form of a part of a circular cylinder and the outer part of which is in the form of an arm St) extending radially of portion 77 of the plate. Portion 77 of the plate is provided with a notch or slot 79 extending parallel to arm 30 but which is offset somewhat from the arm so as to receive the portion of the plunger 17 located at the liatted surface 74. The connection thus afforded between portion 77 of the control plate and the plunger is such as to connect the plate and plunger together for turning about the axis of the plunger while leaving the plunger free for reciprocation along its axis normal to the broad extent of the control plate. The circular inner end of slot 72 and the circular portion 77 of the control plate are of such size that the former forms an accurate bearing for the plate while permitting the plate to be turned throughout its range of adjustment which, in the embodiment shown, is on the order of 90.

Not only does control plate 76 permit turning of the plunger 17, but it retains the plunger against outward escape from the housing 15 once the parts have been assembled by reason of engagement of the shoulder with the lower surface of control plate 76. Preferably, the injector is so located relative to the cam 11 or other actuating means therefor so that at the outer end of the stroke of plunger 17 the shoulder 75 does not quite engage the control plate.

The control plate 76 is turned for adjustment of the quantity of fuel injected by plunger 17 by the following mechanism. Exten-ding around housing 15 centrally of plate 76 there is a shallow peripheral groove 81. Oppositely disposed part-circular spring arms 82 of a control lever 84 are snapped into groove 81 to hold the lever stably in place and free for rotation about housing 15. Lever S4 has a shallow radially extending seat S5 therein which accurately receives the outer end of arm Si) of the control plate 76. Lever 84 has a radially extending arm S6 aligned with seat 85 provided with a longitudinally disposed slot 87 therein. A control link generally shown at 8% is adjustably connected to arm 86, a finger on the link passing through a sleeve adjustably mounted in the slot 87 and being ixedly -held with respect to the arm at the desired distance from the axis of the plunger. Link S9 is connected to a suitable control mechanism such as a throttle lever or pedal for the engine. The throttle linkage (not shown) is arranged so that when the throttle lever or pedal is advanced, members 76 and tid, and thus plunger i7, are turned in such direction as to relieve the fuel injecting pressure from the chamber in the injector at an increasingly later time in the fuel injecting stroke of the plunger. The injector may conveniently be provided with means whereby the angular position of plunger i7 may be readily ascertained from the exterior of the injector. Thus an index mark 91 is shown provided on the housing l5 immediately adjacent groove Si (FlG. 4). The slight gap 9d between the confronting ends of spring arms S2 is aligned with passage 69 in the plunger i7. Index marl; 9i may be positioned, for example, so that the pump delivers a calibrated minimum of fuel at each injecting stroke of the plunger when the gap 90 is aligned with the index mark 9i.

Although only one embodiment of the invention has been illustrated in the accompanying drawings and described in the foregoing specification, it is to be especially understood that various changes, such as in the relative dimensions of the parts, materials used, and the like, as well as the suggested manner of use of the apparatus of the invention, may be made therein without departing from the spirit and scope of the invention as will now be apparent to those skilled in the art.

What is claimed is:

l. A fuel injector comprising a housing having a cylinder therein, a plunger reciprocable in the cylinder, a chamber in the housing axially inwardly of the plunger and communicating with the cylinder, means to feed fuel into the chamber, means to reciprocate the plunger, means to release injecting pressure in the chamber at the end of the fuel injecting stroke of the plunger, means operated by the turning of the plunger about its axis to vary the timing of such pressure release, and means to turn the plunger about its axis comprising a member extending generally radially of the plunger at a zone axially outwardly of the chamber in the housing, a transverse slot in the housing receiving the plunger turning member and permitting its oscillation through a substantial angle about the axis of the plunger7 means connecting the member to the plunger comprising formations on the plunger and member non-rotatably connecting them together while permitting the plunger to reciprocate with respect to the member, and means comprising a band slidably embracing and angularly osciilatable on the housing and connected to the member for turning the member and the plunger about the axis of the latter.

2. A fuel injector as claimed in claim l, wherein the transverse slot in the housing converges radially inwardly and has an inner end which at least partially surrounds the plunger, and the plunger-turning member is a plate having an inner bifurcated end portion straddiing the plunger and having rotatable bearing engagement with the inner end of the slot.

3. A fuel injector as claimed in claim 2, wherein the portion of the slot at least partially surrounding the plunger has an arcuate cylindrical side wall coaxial of the plunger, and wherein the inner end of the plunger-turning plate has arcuate cylindrical bearing surfaces engaging the arcuate cylindrical sidewall of the slot.

A fuel injector comprising a housing having a cylinf er therein, a plunger reciprocable in the cylinder, a chamber in the housing axially inwardly of the plunger and communicating with the cylinder, means to feed fuel into the chamber, means to reciprocate the plunger, means to release injecting pressure in the chamber at the end of the fuel injecting stroke of the plunger, means operated by the turning of the plunger about its axis to vary the timing of such pressure release, means to turn the plunger about its axis comprising a member extending generally radially of the plunger at a zone axially outwardly of the chamber in the housing, a transverse slot in the housing receiving the plunger turning member and permitting its oscillation through a substantial angle about the axis of the plunger, means connecting the member to the plunger comprising at least one axially extended flat outer surface on the plunger and a generally radially directed notch in the member, the plunger being received within said notch with the fiat outer surface of the plunger slidably but not rotatably engaging one inner side surface of the member at the notch for non-rotatably connecting said plunger and member together while permitting the plunger to reciprocate with respect to the member, and means connected to the member for turning the member and the plunger about the axis of the latter.

5'. A fuel injector as claimed in claim 4, comprising resilient means constantly urging the plunger axially outwardly of the housing, and a shoulder on the plunger bounding the axially inner end of the iiat surface on the plunger, the shoulder lying beneath a portion of the member and preventing the outward escape of the plunger from the housing.

6. A fuel injector comprising a housing having a cylinder therein, a plunger reciprocable in the cylinder, the axially outer end of the plunger projecting beyond the outer end of the cylinder, a counterborc in the outer end of the housing surrounding and coaxial with the outer end of the plunger, guide means in the form of a cylindrical guide member accurately fitting and reciprocable in the counterbore, said member having a central opening in a transverse wall thereof through which the outer end of the plunger extends, and means connecting the plunger adjacent its outer end to the guide means to cause the guide means to reciprocate with the plunger and to transmit to the wall of the counterbore lateral thrusts imposed by actuating means for the plunger, said connecting means comprising a tappet removably connected to said plunger for transmitting axial forces thereto and accurately seated in a recess in the outer end of said guide member, whereby said tappet is held against radial movement relative to the guide member.

7. A fuel injector as claimed in claim d, comprising a coil compression spring telescoped about the plunger within the counterbore and abutting a transverse surface of the guide member and the transverse end of the counterbore at its opposite ends, said spring constantly urging the plunger outwardly of the housing.

8. A fuel injector comprising a housing having a cylinder therein, a plunger reciprocable in the cylinder, the axially outer end of the plunger projecting beyond the outer end of the cylinder, a counterbore in the outer end of the housing surrounding and coaxial with the outer end of the plunger, guide means in the form of a cylindrical guide member accurately fitting and reciprocable in the counterbore, means connecting the plunger adjacent its outer end to the guide means to cause the guide means to reciprocate with the plunger and to transmit lateral thrusts imposed on the outer end of the plunger to the wall of the counterbore, said means connecting the guide means to the plunger comprising an enlarged head on the outer end of the plunger, a central opening in the guide member through which the outer end of the plunger extends, and plunger retaining means mounted on the plunger beneath the head thereon and engaging the outer transverse end of the guide member to center the outer end of the plunger with respect to the guide member and to prevent the axially'inward withdrawal of the plunger from the guide member.

9. A fuel injector as claimed in claim f8, wherein the plunger retaining means comprises a laterally slotted radially inwardly extending flange lying beneath and engaging the head, and comprising a central seat on the outer transverse surface of the guide member receiving and centering the plunger retaining means.

1li. A fuel injector as claimed in claim 9, wherein the central seat on the outer transverse surface of the guide member receives, centers, and closes the outer end of the slot in the ange of the plunger retaining means.

fr-l. A fuel injector as claimed in claim 10, wherein the lever means comprises a band embracing the housing of the injector generally in the plane of the member, a generally radially outwardly projecting arm on the band, and a seat receiving the outer end of the arm on the member.

12. A fuel injector as claimed in claim 1l, wherein the housing has a peripheral groove receiving and guiding the band, and the band is resilient and is split at a zone generally diametrically opposite the seat in the lever means.

i3. An injection pump comprising a casing having a bore therein, a plunger reciprocable in said bore, port means in the wall of said casing adapted to be opened and closed by said plunger, means for angularly adjusting said plunger comprising a plate-like member mounted in a radial slot in the wall of said casing for angular movement about the axis of said bore, said member including a bifurcated portion through which said plunger extends for angular movement therewith and axial movement relative thereto and an arm extending radially from said slot, means for reciprocating said plunger in the casing, and means for controlling the discharge of fuel from the pressure chamber in the bore.

14. An injection pump as defined in claim 13, wherein said means for reciprocating the plunger comprises a guide in an enlarged portion of said bore, resilient means between said guide and casing, and means between said guide and the plunger for limiting the movement of the guide relative to the plunger by said resilient means and for transmitting pressure axially to said plunger for actuation of the latter in opposition to said resilient means while transmitting radial forces to the casing through said guide without transmitting such radial forces to said plunger.

15. An injection pump as defined in claim 13, wherein said fuel discharge control means comprises a valve and nozzle assembly secured to said casing and including a spray tip and check valve means for controlling flow from the pressure chamber to said spray tip, said last named means comprising an orificed plate having a flat seat engaged by a resiliently supported valve member with a iiat surface engaging said seat.

16. A reciprocating plunger pump comprising a housing having a bore therein, a plunger reciprocable in said bore, the axially outer end of the plunger projecting beyond the outer end of the bore, a counter-bore in the outer end of the housing surrounding and coaxial with the plunger adjacent the outer end thereof, a guide member reciprocable in said counter-bore, resilient means between said guide member and said housing for actuating said plunger and guide member axially outwardly, and tappet means between said guide member and the plunger for limiting such axially outward movement of the guide member relative to the plunger by said resilient means and for transmitting pressure axially to said plunger for actuation of the latter in opposition to said resilient means while transmitting radial forces to the housing through said guide member without transmitting such radial forces to said plunger.

`17. A reciprocating plunger pump comprising a housing having a bore therein, a plunger reciprocable in said bore, the axially outer end of the plunger projecting beyond the outer end of the bore, -a counterbore in the outer end of the housing surrounding and coaxial with the plunger adjacent the outer end thereof, a guide member reciprocable in said counter-bore, resilient means between said guide member and said housing for actuating said plunger and guide member axially outwardly, and tappet means interlocked with the plunger and telescoped with the guide member for transmittting the axial force of the resilient means from the guide member to the plunger and for transmitting axial forces to the plunger for actuating the latter axially inwardly, said tappet means being adapted to limit said axially outward movement of said guide member relative to the plunger by said resilient means and to transmit radial forces directly through said guide member to the walls of said counterbore.

13. A reciprocating plunger pump comprising a housing having a bore therein, a plunger reciprocable in said bore, the axial outer end of the plunger projecting beyond the outer end of the bore, a counterbore in the outer end of the housing surrounding and coaxial with the plunger adjacent the outer end thereof, a guide member reciprocable in said counterbore, resilient means between said guide member and said housing for actuating said plunger and guide member axially outwardly, tappet means to which forces may be applied for actuating the plunger axially inwardly in opposition to said resilient means, said tappet means being associated with the outer end of said plunger and said guide member so as to limit outward movement of said guide member relative to said plunger and so that components of such forces acting radially with respect to the axis of the plunger are transmitted from said tappet means directly through said guide member to the walls of said counterbore, and means for angularly oscillating said plunger about its longitudinal axis comprising a plate oscillatably mounted in a radial slot in said housing inwardly of said guide member and operably connected with the plunger and an operating member mounted on the housing for oscillating said plate.

19. A fuel injector comprising a housing having a cylinder therein, a plunger reciprocable in the cylinder, a chamber in the housing axially inwardly of the plunger and communicating with the cylinder, means to feed fuel into the chamber, means to reciprocate the plunger, means to release injecting pressure in the chamber at the end of the fuel injecting stroke of the plunger, means operated by the turning of the plunger about its axis to vary the timing of such pressure release, means to turn the plunger about its axis comprising a member extending generally radially of the plunger at a zone axially outwardly of the chamber in the housing, said member having a generally radially outwardly disposed arm thereon, a transverse slot in the housing receiving the plunger turning member and permitting its oscillation through a substantial angle about the axis of the plunger, means connecting the member to the plunger comprising formations on the plunger and member non-rotatably connecting them together while permitting the plunger to reciprocate with respect to the member, and lever means mounted on the housing for rotation about the axis of the plunger and having a driving connection with the arm for turning the member and plunger about the axis of the latter.

20. A reciprocating plunger pump comprising a housing having a bore therein and a radial slot intersecting said bore, a plunger reciprocable in said bore, the axially outer end of the plunger projecting beyond the outer end of the bore, a counterbore in the outer end of the housing surrounding and coaxial with the plunger adjacent the outer end thereof, a guide member reciprocable in said counterbore, resilient means between said guide member and said housing for actuating said plunger and guide member axially outwardly, tappet means for transmitting axial forces to the plunger for actuatting the latter axially inwardly, said tappet means being adapted to limit axial movement of said guide member relative to the plunger by said resilient means and to transmit radial forces directly through said guide member to the walls of said counterbore, and means including an element oscillatable in said slot and operably associated with the plunger for angularly oscillating the plunger about its axis and for limiting outward movement of the plunger by said resilient means.

21. A reciprocating plunger pump comprising a unitary housing having a bore and a transverse slot in the wall thereof intersecting said bore, the inner end wall of said slot being arcuate and being concentric with and having a radius greater than the radius of said bore, a plunger in said bore bridging said slot, means for oscillating said plunger angularly about its longitudinal axis in the bore while permitting the plunger to be reciprocated in the bore, said means comprising a member inserted transversely into said slot for mating engagement with said arcuate end wall, said member having non-rotatable connection with said plunger and being angularly oscillatable with said plunger about said axis, and means oscillatably mounted on the housing for angular oscillation relative thereto about said axis for actuating said member to angularly oscillate the plunger.

22. A reciprocating plunger pump comprising a unitary housing having a bore and a transverse slot in the Wall thereof intersecting said bore, a plunger in said bore bridging said slot, means for oscillating said plunger angularly about its longitudinal axis in the bore While permitting the plunger to be reciprocated 'in the bore, said means comprising a member inserted transversely into said slot, said member having a non-circular passage for slidably but non-rotatably receiving said plunger for non-rotatable connection therewith and being angularly oscillatable With said plunger about said axis, and means oscillatably l@ mounted on the housing for angular oscillation relative thereto about said axis for actuating said member to angularly oscillate the plunger.

References Cited hy the Examiner UNITED STATES PATENTS 1,944,371 1/34 Ritz 239-90 2,144,861 1/39 TruXell 239-88 2,282,562 5/42 Cole.

2,371,787 3/45 Ward 239-88 2,401,579 6/46 Miller' 239-90 2,571,501 10/51 Truxell 239-90 2,590,575 3/52 Rogers 239-88 X 2,717,805 9/55 Siefert et al. 239-90. 2,793,076 5/57 Brehmer 239-90 2,793,078 5/57 Brill 239-88 EVERETT W. KRBY, Primary Examiner.

LOUIS I. DEMBO, Examiner. 

13. AN INJECTION PUMP COMPRISING A CASING HAVING A BORE THEREIN, A PLUNGER RECIPROCABLE IN SAID BORE, PORT MEANS IN THE WALL OF SAID CASING ADAPTED TO BE OPENED AND CLOSED BY SAID PLUNGER, MEANS FOR ANGULARLY ADJUSTING SAID PLUNGER COMPRISING A PLATE-LIKE MEMBER MOUNTED IN A RADIAL SLOT IN THE WALL OF SAID CASING FOR ANGULAR MOVEMENT ABOUT THE AXIS OF SAID BORE, SAID MEMBER INCLUDING A BIFURCATED PORTION THROUGH WHICH SAID PLUNGER EXTENDS FOR ANGULAR MOVEMENT THEREWITH AND AXIL MOVEMENT RELATIVE THERETO AND AN ARM EXTENDING RADIALLY FROM SAID SLOT, MEANS FOR RECIPROCATING SAID PLUNGER IN THE CASING, AND MEANS FOR CONTROLLING THE DISCHARGE OF FUEL FROM THE PRESSURE CHAMBER IN THE BORE. 